This invention relates to vehicles, and more particularly to an arrangement and mounting system for the drive train of a vehicle.
A construction-type vehicle such as an extendible boom forklift typically includes a central frame member which extends along a longitudinal axis in a front-rear direction. A pair of steerable driven wheels are mounted to an axle, which in turn is mounted toward the rearward end of the central frame member. A pair of steerable driven wheels are also mounted to the central frame member toward its forward end. A pair of uprights extend from the rearward end of the central frame member rearwardly of the rear axle, and an extendible boom assembly is pivotably mounted to and between the uprights. The extendible boom terminates in a forward end located forwardly of the front wheels, and is raised and lowered relative to the central frame member by extendible and retractable hydraulic cylinders interconnected between the extendible boom assembly and the central frame member.
In a vehicle such as this, it has been known to mount the engine on the central frame member, so that the engine output is coincident with the centerline of the vehicle as defined by the longitudinal axis of the central frame member. A transmission is also mounted to the central frame member, defining an input and an output which lie along the centerline of the machine, and the transmission is drivingly interconnected with the engine output. The cab is supported off the side of the central frame member, and thus has a relatively narrow width limited by the amount of space between the side of the central frame member and the outer extent of the wheels.
An increase in the width of the cab has been found to enhance the ergonomics involved in operation of the vehicle. However, since the location of the outer extent of the cab is dictated by the outer extent of the wheels, any increase in cab width thus requires more of the cab to be located more toward the centerline of the vehicle. The increased space requirements for the cab thus encroaches on the space typically occupied by the engine and transmission in the prior art configuration.
It is an object of the present invention to provide a system for mounting a drive train, including an engine and a transmission, in a vehicle having a central frame member, in which the engine and transmission are placed so as to accommodate a relatively wide operator cab mounted to the central frame member. Another object of the invention is to provide a drive train mounting system which minimizes the height of the compartment within which the engine is mounted, and which does not alter the overall width of the vehicle or adversely effect the turning angle of the front wheels. Yet another object of the invention is to provide a drive train arrangement which can be made into a subassembly which is mounted as a unit to the frame or other support structure of the vehicle. A further object of the invention is to provide a drive train mounting arrangement which accommodates placement of a cooling system directly adjacent the engine. A still further object of the invention is to provide a drive train mounting arrangement which provides input power to the driven wheels along the centerline of the vehicle.
In accordance with one aspect of the invention, a power system or drive train for a vehicle having a central frame member extending along a longitudinal axis in a front-rear direction includes a drive train support structure mounted to the central frame member, an engine mounted to the support structure and including an output, and a transmission mounted to the central frame member. The engine is laterally offset relative to the longitudinal axis of the central frame member, and the transmission includes an input and an output lying along an axis coincident with the longitudinal axis of the central frame member. A power transfer arrangement extends between and drivingly interconnects the engine output and the transmission input, for providing power to the transmission from the engine. The support structure is preferably in the form of a frame assembly mounted to the central frame member and extending laterally therefrom. The support structure and the central frame member cooperate to define a drive train mounting area or space within which the drive train components are received. The central frame member defines a forward portion and a rearward portion, and the support frame assembly is located between the central frame member forward and rearward portions. The forward and rearward portions of the central frame member each preferably define an internal passage. The transmission output is interconnected with a front drive shaft which extends into and through the internal passage in the forward portion of the central frame member, and with a rear drive shaft which extends into and through the internal passage in the rearward portion of the central frame member. The central frame member preferably includes a side wall extending between and forming a part of each of the central frame member forward and rearward portions, and the support frame assembly extends laterally from the side wall. The engine and the transmission are oriented in a side-by-side configuration, and the engine preferably extends along a longitudinal front-rear axis substantially parallel to the longitudinal axis of the transmission input and output. The transmission input is located at a first end of the transmission for interconnection with the power transfer arrangement, and power is output from both ends of the transmission through the front and rear drive shafts. The engine output is located at one end of the engine, which is laterally spaced from the input end of the transmission. The power transfer arrangement preferably includes a power transfer casing which is operable to structurally interconnect the output end of the engine with the input end of the transmission. The power transfer casing is mounted at one end to the support frame assembly, and is mounted at its opposite end to the side wall defined by the central frame member. A mounting member extends between and interconnects the engine and the transmission at a location spaced from the power transfer casing. The mounting member extends under the transmission, and defines an end which is mounted to the central frame member side wall. The engine is secured to an opposite end defined by the mounting member. A separate mounting member is interconnected between the engine and the support frame assembly at a location spaced from the power transfer casing.
In accordance with another aspect of the invention, a vehicle includes a central frame member carrying at least one, and preferably two, sets of driven wheels, and extending along a longitudinal axis in a front-rear direction. A pair of side frame assemblies are mounted to the central frame member, extending laterally therefrom in opposite directions. An operator cab is mounted to a first one of the side frame assemblies, and an engine is mounted to a second one of the side frame assemblies. The engine includes an output, and extends along a front-rear axis laterally offset from the longitudinal axis of the central frame member. A transmission is interconnected with the central frame member, and includes an output drivingly interconnected with the set of driven wheels. The transmission includes an input laterally offset from the engine output, and a power transfer arrangement is interposed between and drivingly interconnected with the engine output and the transmission input for supplying power to the transmission from the engine. The inner extent of the operator cab is located immediately adjacent the central frame member and the transmission, such that the engine is spaced laterally outwardly from the inner end of the operator cab. Details of this aspect of the invention are as summarized above.
In accordance with yet another aspect of the invention, a drive train system for a vehicle includes an engine extending along a longitudinal axis and having an output, a transmission having an input and extending along a longitudinal axis substantially parallel to the longitudinal axis of the engine and laterally offset from the engine, and a power transfer arrangement interposed between and drivingly interconnected with the engine output and the transmission input. The engine and the transmission are preferably arranged in a side-by-side manner. The engine output is located at a first end defined by the engine, and the transmission input is located at a first end defined by the transmission. The power transfer arrangement is interconnected with the first ends of the engine and transmission. The transmission defines a second end opposite its first end, and includes an output located at its first end and an output located at its second end. The power transfer arrangement preferably includes a casing mounted to the first end of the engine and to the first end of the transmission, and the power transfer casing is operable to structurally interconnect the engine and the transmission. A structural mounting member is spaced from the power transfer casing, and is also operable to structurally interconnect the engine and the transmission. In this manner, the engine, transmission and power transfer arrangement are interconnected into a subassembly which can be mounted to the vehicle frame as summarized above.
The invention also contemplates a method of mounting a power system or drive train to a vehicle, substantially in accordance with the foregoing summary.